Black bloc

A black bloc is a tactic for protests and marches where individuals wear black clothing, scarves, sunglasses, ski masks, motorcycle helmets with padding, or other face-concealing and face-protecting items.^[1][2] The clothing is used to conceal marchers’ identities, allow them to appear as one large unified mass, and promote solidarity.

The tactic was developed in the 1980s in the European autonomist movement‘s protests against squatter evictions, nuclear powerand restrictions on abortion among other things.^[1] Black blocs gained broader media attention outside Europe during the 1999 anti-WTO demonstrations, when a black bloc damaged property of GAP, Starbucks, Old Navy, and other multinational retail locations in downtown Seattle.^[1]

Wikipedia